1. Field of the Invention
The present invention relates to a portable wireless terminal, and more particularly to an antenna apparatus for a portable wireless terminal.
2. Description of the Related Art
Recently, portable wireless terminals have been developed toward miniaturized, multi-functional, lightweight, and low power consumption characteristics. An antenna apparatus is an essential part of the portable wireless terminal, thereby determining a speech quality of the terminal.
Conventionally, the antenna apparatus for a portable wireless terminal includes the combination of a helical antenna and a whip antenna. The helical antenna operates alone in a standby mode or under good radio propagation environments, and the whip antenna is drawn out from a main body of the terminal and operates simultaneously with the helical antenna in a communication mode or under poor radio propagation environments. In the antenna apparatus, the helical antenna with a comparatively larger volume is fixed to an upper end of the main body of the terminal, and the whip antenna is installed in the main body of the terminal so as to be drawn into and out from the terminal when desired, thereby operating in a drawn-out state.
The portable wireless terminals are manufactured as several types, i.e., bar-type terminals, flip-type terminals, and folder-type terminals. In case of the folder-type terminal, a folder is rotatably closed into a main body in the standby mode, thereby having an advantage in terms of miniaturization. Further, the folder is rotatably opened from the main body in the communication mode, thereby assuring a sufficient distance between a transmitting unit and a receiving unit. Therefore, the folder-type terminal is mainly selected by users.
FIG. 1 is a perspective view of a conventional folder-type terminal 100. As shown in FIG. 1, the conventional folder-type terminal 100 comprises a main body 101 including a main board 103 installed therein, a folder 102 rotatably connected to the main body 101, and a hinge device (not shown) for rotatably connecting the folder 102 to the main body 101. The folder 102 is rotated about a hinge axis A, thereby being opened from and closed into the main body 101. An antenna apparatus 110 is installed on one side (i.e. a first side) of an upper end of the main body 101.
The antenna apparatus 110 includes an antenna housing 111 having a helical antenna (not shown) installed therein and fixed to one side of the upper end of the main body 101, and a whip antenna 113 drawn into and out from the main body 101 via the antenna housing 111. That is, the aforementioned antenna apparatus 110 includes the combination of the helical antenna (not shown) and the whip antenna 113.
The helical antenna accommodated by the antenna housing 111 is connected to the main board 103, thereby operating in a communication mode under good radio propagation environments or in a standby mode. In case the whip antenna 113 is drawn into the main body 101, the whip antenna 113 is electrically isolated from the main board 103. On the other hand, in case the whip antenna 113 is drawn out from the main body, the whip antenna 113 is electrically connected to the main board 103, thereby operating simultaneously with the helical antenna in a communication mode or under poor radio propagation environments.
In order to prevent a fading effect, the portable wireless terminal 100 may further include a diversity antenna 115a or 115b serving as an anti-fading antenna. Herein, the fading effect means a reduction of a signal quality or a transmission rate, due to a change of a radio wave transmission medium, diffraction propagation, or a phase difference generated when a radio wave transmitted from one point is received via more than two routes.
The diversity antenna 115a or 115b is typically installed on either the upper end of the main body 101 or a lower end of the main body 101, typically on a second side that is opposite from where the antenna housing 111 is fixed.
The portable wireless terminal 100 detects the optimum signal by combining signals received by each of the diversity antenna 115a or 115b and the antenna apparatus 110, thereby preventing the fading effect and improving the signal quality. As the diversity antenna 115a or 115b is separated from the antenna apparatus 110, the anti-fading effect is proportionately improved.
However, the conventional antenna apparatus for the portable wireless terminal is protruded from the main body of the terminal, thereby being difficult to carry and being easily broken if the terminal is dropped. Further, the protruding structure of the antenna apparatus from the main body of the portable wireless terminal limits the designing possibilities of the antenna apparatus and mobile terminal. Moreover, it is difficult to assure a sufficient space required to install the diversity antenna.